Machine-to Machine (M2M)/Machine Type Communications (MTC) applications are applications where machines communicate with each other directly without human intervention. Examples of applications include smart metering, safety applications, health monitoring, fleet management, data applications and remote applications.
The MTC devices can be embedded in cars, consumer electronic devices, vending devices, etc. These devices are large in number and are wide spread. The applications should communicate through widely deployed networks connecting the MTC devices to the Internet forming Internet of Things (IoT). While some existing MTC deployments use short range communications, it would be ideal to use cellular networks as the infrastructure is established in a stable manner and can support a large number of MTC devices.
The enormous amount of signaling flow generated by the large number of MTC devices trying to connect to the network at the same time leads to congestion in radio access network (RAN) and the core network (CN). This in turn causes intolerable delays, packet loss and also service unavailability. Also, congestion in MTC would also affect the non MTC devices.
Generally at the RAN side, the congestion occurs when a large number of MTC devices try to communicate concurrently with the eNodeB. For example, MTC devices which are used for monitoring (bridge monitoring or rainfall/flood monitoring) will transmit the monitored data concurrently. As the devices are connected to the same eNodeB, using the same common channels (Random accesses), can lead to congestion. Consequently the network should be optimized to support these communication requests from the devices simultaneously.
In Release 11, 3GPP System Architecture working group 1 (SA1) has defined system aspects and technical specifications for MTC device to device communication, group based services and possible enhancements to improve the network for MTC. Various solutions such as Access Class Barring schemes, Separate Random Access Channel (RACH) resources for MTC, Dynamic allocation of RACH resources, MTC Specific Back off scheme, slotted access and the like are proposed by the 3GPP to overcome the problem of congestion. These solutions from 3GPP will distribute the RACH load. However, in case of super dense deployment of Pico cells it will either impair the M2M devices or Human to Human (H2H) users.
The deployment scenarios herein take into consideration a combination environment where there is constant movement of MTC devices alongside the static MTC devices. This creates congestion at the RAN due to random access contention during uplink transmission where multiple MTC devices try to send data to the network. Further, during downlink transmission and capacity should be improved while supporting large number of MTC devices along with the existing H2H interaction in downlink transmission. Further, the RACH burst from MTC devices will overload the RACH access at eNodeB which deprives the cellular users from normal service due to overloading of RACH by a higher density of M2M devices.
In view of the foregoing, there is a need for an MTC device friendly system and method for minimizing RACH load and provide accesses to MTC devices in MTC based communication.